6 replies to this topic

[NV Racer]

It's getting hard to find straight 1.6 donors with manual transmission. I have found several automatics. Swapping the mechanical parts is straightforward. I have questions about wiring and ECU. Can I swap my ECU over to auto donor using existing auto harness? I read that neutral safety switch needs to be spliced to clutch pedal switch. I read somewhere that the car would not start if you do not swap harness with ECU. Trying to save as much time as possible to get swap done before season starts. Thanks for any advice.

[Alberto]

I believe you need to swap the harness

[Alberto]

adding some additional detail since I had some automatic parts in my hands over the weekend...

 

The injector harness plugs are different between the auto and manual.  The manual has a 6 pin connector at the main wiring harness that plugs into the injector harness while the automatic has 8 pins.  So you need the main harness from a manual car to plug into the correct injector harness.  

 

Also, the throttle position sensor is different.  4 pins for the automatic vs 3 pins for the manual.  Not sure if the actual throttle body is different though.

 

Then of course, the camshafts are different on the automatic vs manual - and a few other changes that can be googled since I don't know them off the top of my head.

[NV Racer]

I saw a post that using the automatic Throttle body on the manual transmission engine saves having to change the ECU. Not sure I have the time to swap the wiring harnesses over to new donor. Using the Auto ECU would cause car fail tech. I read that Auto ECU's have better low end torque and better A/F without having to tweak mass airflow sensor

[Alberto]

I don't think the auto ECU provides 'better' low end torque.  On the 1.6, I think that is from the different camshafts that the auto runs compared to the manual.  Kinda how GM uses a different cam on their truck motors to improve low end torque vs top end power.

[Dave D.]

I always heard that the engine in the NA auto cars had lower compression and smaller cams as the transmission used in the NAs were very weak.

[NV Racer]

Thanks for responses. I found a very good Manual '91 donor so moot point now.